Coin controlled cycle starter

ABSTRACT

The coin-controlled cycle starter utilizes a standard singlecoin slide for activating the machine controlled by the starter, although more than one proper coin or token is required to effect an activation. Without any change in the standard slide, it is caused to collect two or more coins for each machine activation, this being accomplished by the simple addition of a second ratchet wheel to the cycle starter mechanism.

United States Patent [72] Inventor Mitchell A. Hall [56] References Cited Ft. Thomas, Ky. UNITED STATES PATENTS N0. }90,g i969 3,237,466 3/1966 Purtilo l94/9(T) e 3,260,339 7 i966 Greenwald et 1 194 92 451 Patented Jan. 26, 1971 a [73] Assignee Monarch Tool 8: Manufacturing Company Primary Exammer stnley Tonberg covingmn, Att0rney-J Warren Kmney, Jr. a corporation of Ohio.

[54] COIN CONTROLLED CYCLE STARTER 18 Claims, 9 Drawing Figs.

[52] U.S.Cl 194/1 51 1m. c1 G07f 1 00 50 Field of Search 194/9(T),

ABSTRACT: The coin-controlled cycle starter utilizes a standard single-coin slide for activating the machine controlled by the starter, although more than one proper coin or token is required to effect an activation. Without any change in the standard slide, it is caused to collect two or more coins for each machine activation, this being accomplished by the simple addition of a second ratchet wheel to the cycle starter mechanism.

PATENTEU JAN26|97| 3557.926

SHEET 1 OF 2 whim I I 1 94 64 62 j 72 L i '4 98 INVENTOR 42 46 22 MITCHELL A. HALL FIG; 3

PATENTED JAN26 I97! 35571926 sum 2 0F 2 //V VE' N TOR MITCHELL A. HALL COIN CONTROLLED CYCLE STARTER This invention relates to a coin controlled cycle starter for automatic electric contactors or switches designed to open and close a multiplicity of electric circuits in predetermined succession, during a specified period of time. Such automatic electric switches or contactors generally comprise a series of discs or drums each fixed upon a common shaft which is rotated by means of a synchronous electric motor. The discs or drums usually are notched peripherally to cooperate with movable contacts serving to open or close electric circuits, depending upon the nature and extent of the disc or drum notches.

In switches or contactors of the character mentioned, the driven shaft carrying the contact actuating discs is rotated very slowly through a cycle of operation which in extent is less than a full rotation of the shaft. Rotation of the shaft is restarted, after completion of each cycle, by manually closing the circuit of the synchronous motor which drives the shaft, this closing of the motor circuit being effected, as by way of example, byactuating a coin slide after placing proper coins or tokens in the slide. The shaft continues to rotate, through less than a full rotation, until a full succession of switching operations is completed; then with a final switch opening, the electric circuit of the synchronous motor is broken automatically to complete the cycle of operation and to immobilize the shaft in readiness for another manual closing of the motor circuit through the agency of the coin slide.

Switches and coin slides as above mentioned may be employed in connection with service machines such as clothing washers, dryers, and the like, or in other machines designed to perform a function or service upon the deposit of coins or tokens by a patron. In the case of washing machines which are automatic, the control switch will ordinarily include a multiplicity of electric contacts and circuits, which open and close in predetermined order, to start and stop a series of washing, draining, tumbling, rinsing and other necessary operations constituting a cycle of operation performed within a predetermined time period governed by a set of stop contacts controlling the synchronous electric motor of the switch mechanism. 1

An object of the present invention is to provide reliable and effective means for initiating a cycle of machine operation, through the agency of a coin slide, and which is not subject to damage or destruction due to abusive treatment or deliberate attempts to disable the machine.

Another object of the invention is to provide coin slide controlled means of a simple and rugged character, for initiating a cycle of timed operation for automatic machines, only after executing a plurality of slide actuations each requiring the deposit of a proper coin or token.

Another object of the invention is to provide means for initiating a cycle of timed operation for automatic machines, characterized by simplicity of construction and operation, and minimal maintenance attention.

A further object of the invention is to provide an improved cycle starter requiring more than one full advancement of a coin slide for initiating the cycle, which improved starter may quickly and easily be substituted for conventional starters of the type requiring a single full advancement of the coin slide to activate existing service machines.

Another object is to facilitate and expedite adjusting the cycle starter for accurate and efficient performance, without resort to painstaking and time-consuming labor.

The foregoing and other objects are attained by the means described herein and illustrated upon the accompanying drawings, in which:

FIG. I is a side elevational view, partly broken away, showing a coin slide and timer switch combination embodying the present invention, and which may be used to control the operation of a service machine, such as an automatic washer, for example.

FIG. 2 is a top plan view of the device of FIG. 1, partly broken away in the interest of clarity of disclosure.

FIG. 3 is an enlarged cross section taken on line 3-3 of FIG. 2.

FIG. 4 is an inverted cross section taken on line 44 of FIG. 3, showing the improved starter in home position and ready for an initial actuating impulse.

FIG. 5 shows the starter of FIG. 4 following a first advancement of its actuator arm.

FIG. 6 shows the starter with its actuator arm restored to home position after the first advancement.

FIG. 7 shows the starter following a second advancement of its actuator arm. 7 i I FIG. 8 shows the starter with its actuator arm restored to home position after the second advancement.

FIG. 9 shows the starter following a third advancement of its actuator arm, which effects an actual starting of the timer switch.

Referring to the drawings, the numeral 14 indicates a conventional timer switch which may be of the type disclosed in US. Pat. Nos. 3,011,04l; 2,245,763; 2,! 18,427 or 3,064,485. The switch has a multiplicity of electric terminal pairs l6, l8 and 20, others of which are not shown, said pairs of terminals being adapted for connection withvarious electrical devices of a service machine, to control the machine and its operating sequence. If the service machine is an automatic washer, for example, the switch terminals maybe connected to various electrical devices in the machine for controlling the sequence and duration of washing, draining, tumbling, rinsing, and perhaps other necessary functions characterizing the machine.

Within the housing of the timer switch 14 is an upright shaft 22, adapted to be slowly rotated by means of a synchronous electric motor 24. Motor 24 is to be energized throughout a complete cycle of operation of the machine controlled by the timer switch, which may be a matter of twenty minutes, for example, and during that time period the shaft 22 will be rotated less than a full tum. At the end of the time period, the timer switch will open the circuit of motor 24 to immobilize the motor and the switch shaft 22, the complete cycle of operation of the service machine having been completed.

' To begin another cycle of operation of the service machine, a patron is required to deposit proper coins or tokens in the slide plate 26 of a coin slide 28, and advance the slide plate a predetermined number of times to the fully advanced position thereof. In the device herein illustrated by-way of example, a cycle of operation may be started only as a result of three successive slide plate advancements, each accompanied by a proper coin or token deposit. Thethird full advancement of the slide plate actuates a restarting mechanism for the timer switch and its synchronous electricmotor 24. Then, as before stated, the service machine will perform the desired or expected cycle of operation for which the patron has paid. It must be understood, however, that the timer switch and its driving motor 24 will not respond to a single fulladvancement of coin slide plate, nor to a number of full advancements fewer than the mechanism is designed to require as will be explained. I

Within the timer switch housing may be located a series of discs or dru'ms, not shown, which are rotatable with shaft 22 and which in rotating will close and open the electrical circuits of the various terminals, including those denoted 16, 18, 20, in predetermined sequence and for predetermined periods of time, as may be required in order to properly actuate the several constituents of the service machine, until its cycle of operation is completed. Thereupon, the synchronous electric motor 24 will be deenergized until the same or another patron actuates the coin slide 28 a proper number of times with the deposit therein of a proper coin or token for each actuation.

The coin slide may be mounted upon a shelf 30 or elsewhere within a box 32 which houses also the cycle timer l4 and its associated parts. The cycle timer conveniently may be fixedly supported upon a side of the box by means of an'angle bracket 34 and screws 36. As shown by FIGS. 1 and 2, the coin slide and the cycle timer are positioned within box 32, so that a freely rotatable roller 38 fixed upon the inner end of coin slide plate 26 will upon advancement of the coin slide, strike and move an actuator arm 40 of the cycle starting mechanism for the timer switch.

FIG. 5 shows the actuator arm 40 moved from the home position of FIG. 4, by a full advancement of roller 38 carried by the coin slide plate. The normal inactive or home position of the actuator arm and coin slide plate, is as indicated by FIGS. 1 and 2. As is usual, the coin slide plate is urged always to the retracted position by the action of a torsion spring 29, FIG. 2.

The function of the actuator arm 40 is to place the switch shaft 22 in a position to close the synchronous motor contacts each time that the coin slide is advanced a predetermined number of times in excess of one, to initiate a cycle of machine operation. It is necessary to understand, in this connection, that a complete cycle of machine operation involves rotation of shaft 22 through a number of circle degrees less than 360 degrees, so that at the end of any cycle, the shaft will have stopped short of its cycle-starting position. Consequently, it is necessary to advance the shaft manually, through the agency of the coin slide, through the number of remaining circle degrees required to bring the shaft into position for closing a pair of contacts in the synchronous motor circuit, to repeat the operating cycle.

The extent to which the shaft 22 requires manual rotation by means of the actuator arm and the coin slide, in order to reach the cycle-starting position, will be a constant factor in any given machine. However, in different machines having dif ferent functions or operating periods, the distance through which the shaft requires manual rotation in order to reach cycle-starting position, may vary according to the nature and extent of the operating cycle.

Solely for the purpose of illustration or example in connection with the present disclosure, it may be assumed that a full operating cycle requires a 240 degree rotation of shaft 22 for closing and opening the various contacts of the timer switch, until the synchronous motor is stopped by reason of the breaking of its electrical circuit by the timer switch. Accordingly, there remains 120 degrees of rotation of the shaft through which the shaft must be advanced manually by the coin slide, in order to restore the shaft to starting position for subsequent cycling by closing the synchronous motor circuit.

Referring to FIG. 3, it will be noted that shaft 22 at its upper end carries one or more flats 42, against which may impinge the set screws 44 of a centrally bored hub 46, to secure the hub for rotation with the shaft. Fixed to the hub, concentri' cally with shaft 22, is a ratchet wheel 46. The ratchet wheel may have a single tooth 48, FIG. 4, in the specific apparatus il lustrated by way of example, adapted to be engaged by a pawl 50, under certain conditions to be later explained. Pawl 50 is pivotally mounted at 52 upon one face of an adjustment plate or disc 54, which latter is centrally apertured at 56 to loosely surround the upstanding neck 58 of hub 46.

Upon the upper planar face 60 of disc 54 rests the actuator arm 40, said arm being apertured at 62 intermediate its ends, to loosely surround an upstanding concentric neck 64 of disc 54 whereby the actuator arm under certain conditions may be rotated to adjusted positions relative to the disc. A washer 66 applied tightly about the neck 58 of hub 46, holds the actuator arm in position upon the planar face 60 of disc 54. Washer 66 might as well be a detachable split retaining ring.

An adjustment means is provided for selectively fixing the actuator arm 40 upon the face of disc 54, in different diametral positions upon the disc. Such adjustment means may comprise a screw 70 passing through aligned holes 72 and 74 formed in the disc and in a clamp member 68, respectively. By this or any equivalent means, the actuator arm may be locked upon the disc in various adjusted positions of rotation.

The character 78 indicates a tension spring having opposite ends anchored to pawl 50 at 80, and to a lug 84 on discji whereby the pawl is yieldingly urged constantly in the direction of shaft 22 and wheel 46. The actuator arm 40 may be limited in its swinging movement, as by means of stationary spaced stops or posts 86 and 88 suitably mounted upon the top of the timer switch casing. The actuator arm normally is yieldingly urged against stop 86 by means of any acceptable form of spring, such as the wire loop spring 90. The normal or home position of the arm is shown in FIG. 4, whereas FIG. 5 shows it in the displaced position resulting from a full advancement of the coin slide plate 26.

An important feature of the present structure, is the incorporation of a secondary ratchet wheel or skip wheel 81, which loosely surrounds the hub 58 and rests against one face of the single-tooth ratchet wheel 46. A spring washer 87 resting upon hub 58, keeps the two ratchet wheels in face contact, without enforcing rotation of the ratchet wheels in unison.

The skip ratchet wheel 81, FIG. 4, has at least one, but preferably two, sets of peripheral teeth. Each set comprises one deep tooth 83 and one or more shallow teeth 85, 85. By way of example, the drawings show two shallow teeth 85, in succession with one deep tooth 83 though it should be understood that a set may consist of more than two or less than two shallow teeth, and one deep tooth, as will be explained.

The root of each deep tooth 83, and the root of tooth 48 of the shaft-driving wheel 46, can be brought into substantial re gistry or coincidence (see FIG. 8), so that pawl 50 will act upon both teeth 83 and 48 simultaneously (FIG. 9), to effect a partial rotation of shaft 22 in counterclockwise direction as actuator arm 40 moves from the broken line position to the full line position of FIG. 9. As previously explained, such movement of the actuator arm results from a full advancement of the coin slide plate 26. None of the shallow teeth 85 is deep enough to ever register with the driving tooth 48 of wheel 46.

In the light of the foregoing explanation, the method of operation is seen to be as follows.

A patron inserts a proper coin or token in the coin slide, whereupon the slide plate may be manually extended to cause roller 38 to strike actuator arm 40, and to move said arm from the position of FIG. 4 to the position of FIG. 5, against the resistance of spring 90. Said movement of arm 40 is accompanied by a like movement of disc 54 upon which is pivoted the pawl 50. Accordingly, pawl 50 will be caused to engage a shallow tooth 85 in its immediate path, for effecting a partial rotation of ratchet skip wheel 81. As FIGS. 4 and 5 plainly indicate, the driving tooth 48 of ratchet wheel 46 remains out of reach of pawl 50 during this entire span of movement of the pawl and the actuator arm, so that no rotational movement is imparted to switch shaft 22. Therefore, the entire initial operation of the coin slide has performed no function other than those of advancing the skip wheel 46 a distance of one tooth, and collecting a coin from the patron.

FIG. 6 illustrates the return of arm 40 to home position, as the result of withdrawing the coin slide plate. The skip ratchet wheel deep tooth 83 is seen to have been advanced one tooth beyond the FIG. 4 position.

Now, the patron inserts a second coin or token of proper kind, enabling him to again fully advance and retract the coin slide plate 26. This results in movement of actuator arm 40 from the position of FIG. 6, to the position of FIG. 7, and to the home position of FIG. 8. During this impulse, pawl 50 has again engaged a shallow tooth 85 (FIG. 6), causing a singletooth advancement once again of skip wheel 46, with no motion imparted to timer switch shaft 22 because of inaccessability of tooth 48 to pawl 50 during that impulse. Accordingly, the net result of the second actuation just described was to again take a coin from the patron, and advance the ratchet skip wheel 81 a distance of one tooth.

It should now be noted that termination of the second actuation left the mechanism in the condition of FIG. 8, where a deep tooth 83 of the skip wheel now coincides with the drive tooth 48 of ratchet wheel 46. Therefore a third coin slide actuation, requiring of course a third coin, will advance pawl 50 against both teeth 48 and 83 according to FIG. 9, causing the shaft-supported wheel 46 to partially rotate the timer switch shaft 22, to the extent necessary for energizing the synchronous electric drive motor 24. Motor 24, as before explained, carries the timer switch through a complete cycle of service machine operation.

The mechanism operative asjust explained, provides a simple means of adjusting the service charge to changing economic conditions, without the need for making extensive physical changes in the mechanism. By merely replacing the skip wheel 8] with others having a different arrangement of teeth, the mechanism can be rendered operative for service upon the deposit of two, three or more proper coins in a coin slide, without alteration of the coin slide. in the example given, the coin slide collects three coins before placing the service machine in operation.

it is noted that arm 40 remains in the home position throughout the operating cycle of the timer switch, as the shaft 22 and ratchet wheel 46 progress under the moving influence of motor 24.

The rectangular opening 94 of the actuator arm 40 (FIG. 7), is merely a socket in which the loop 96 of spring 90 may be anchored. Spring 90 may have intermediate convolutions 98 loosely surrounding the hub 46 as shown.

The character 100, FIGS. 1 and 2, indicates a guide on bracket 34, having an upturned lip 102, the purpose of which is to stabilize the coin slide plate 26 when extended and exerting force upon the actuator arm 40. The guide may not be necessary if the slide plate is made sufficiently rigid to resist bending or upward deflection upon advancement against the actuator arm.

While it is apparent that the present disclosure is complete and ample for the purposes of the present invention, further information of a secondary nature, or concerning matters not here deemed relevant, may be obtained by referring to US. Pat. No. 3,064,485, issued Nov. 20, 1962.

lclaim:

l. The combination which comprises: a cycle starter for starting and controlling a series of machine operations, said starter including a rotatable shaft, an electric motor in driving relation to said shaft, and a motor circuit including electric contact means closable to energize said motor incident to an initial manual part-rotation of said shaft, and to deenergize said drive motor as the shaft reaches a terminal limit of rotation; a coin slide including a slide plate receptive of a coin, and means for testing the coin, said slide plate having an end fully advanceable then fully retractable whenever a coin in the slide plate passes testing; and means operative to initiate a partrotation of the shaft for energizing said drive motor only after at least two successive full advancements of the slide plate.

2. The combination as defined by claim 1, wherein is included means for supporting independently of the coin slide, the rotation-initiating means aforesaid.

3. The combination as defined by claim 1, wherein the cycle starter shaft provides support for the rotation-initiating means aforesaid.

4. The combination as defined by claim 1, wherein is provided means on the cycle starter for supporting the rotationinitiating means aforesaid.

5. The combination as defined by claim 1, wherein said rotation-initiating means and said coin slide are normally out of physical contact with one another.

6. The combination as defined by claim 5, and wherein said rotation-initiating means includes an actuator arm movable between a home position in the path of advancement of the coin slide plate, and a position of displacement about the starter shaft axis, a pawl movable correspondingly with said actuator arm, and a pair of rotary ratchet wheels surrounding the cycle starter shaft, one of said ratchet wheels being fixed relative to said shaft, and the other of said ratchet wheels being rotatable as an idler relative to said shaft, and an arrangement of teeth on said ratchet wheels insuring tooth-bytooth rotation of the idler wheel with full displacement of the actuator arm, and a partial rotation of said one ratchet wheel unitarily with the shaft, only after a plurality of single tooth rotary impulses of the idler wheel have been completed.

7. The combination as defined by claim 6, wherein advancement of the slide plate is performed in a plane at approximate right angles to the axis of the cycle starter shaft.

8. The combination as defined by claim 3, wherein advancement of the slide plate is performed in a plane at approximate right angles to the axis of the cycle starter shaft.

9. The combination as defined by claim 6, which includes spring means operative normally to retract the coin slide and to urge the actuator arm toward home position.

10. Cycle starting mechanism for a motor-driven electric contactor including a main shaft, an electric motor, a switch connected to said motor so as to control its operation, said motor connected to said main shaft so as to rotate it in one direction, said switch energizing said motor while it drives said main shaft and contactor from a starting position to a terminal position, through a circle arc less than a full circle; said starting mechanism comprising a toothed ratchet wheel fixed relative to the main shaft of the contactor, a selectively rockable actuator arm loosely mounted for rotation about the shaft, between a home position and a position of displacement, means tending to constantly urge said actuator arm toward the home position, a pawl spring biased toward engagement with the tooth of the ratchet wheel, means mounting the pawl for bodily movement with the actuator arm, the swing of the actuator arm being substantially complementary in extent to the arc traversed by the shaft in power rotating from the starting position to the terminal position aforesaid, and means operative to preclude engagement of the pawl with the tooth of the ratchet wheel, until the actuator arm has been rocked to and from the displaced position at least once without concurrent movement of the main shaft.

11. The mechanism as defined by claim 10, wherein is included in combination, selectively adjustable means for fixing the actuator arm in different rotated positions relative to the tooth upon the ratchet wheel.

12. In combination, a motor-driven electric contactor including a main shaft rotatable through a complete circle, said shaft being power-rotatable in one direction from a starting position to a terminal position through a circle arc less than a full circle in extent, a hub detachably fixed upon the shaft for rotation therewith, a toothed drive ratchet wheel drivingly fixed relative to the hub, an adjacent multiple-tooth skip ratchet wheel loosely surrounding the hub for concentric rotation relative to the drive ratchet wheel, one of said skip ratchet wheel teeth having a deep root dimension such as to effect registration with the tooth of the drive ratchet wheel, and other teeth on the skip ratchet wheel having each a shallow depth short of effecting registration with the tooth of said drive ratchet wheel, an adjustment plate apertured to loosely surround the hub for relative rotation, and an actuator arm apertured to surround the shaft for swinging movement about the main shaft axis and in close proximity to the adjustment plate, a pawl pivoted upon the adjustment plate, and means yieldingly urging the pawl toward both ratchet wheels to engage the deep tooth of the skip ratchet wheel concurrently with engaging the toothof the drive ratchet wheel whenever said deep tooth and said drive ratchet wheel tooth are in registry, and to engage only the shallow tooth aforesaid whenever said deep tooth and said drive ratchet wheel tooth are out of registry, and means for selectively clamping the arm in various rotated positions upon the adjustment plate.

13. The combination as defined by claim 12, including yielding means for constantly urging the actuator arm in a direction of rotation counter to that of the main shaft, and stationary stop means for limiting rotation of the arm by said yielding means last mentioned.

14. The combination as defined by claim 13, wherein the number of shallow teeth on the skip ratchet wheel is at least equal to or greater than the number of deep teeth on said skip ratchet wheel.

15. The combination as defined by claim 12, wherein the shallow teeth on the skip ratchet wheel outnumber the deep teeth thereon.

16. The combination as defined by claim 13, wherein the shallow teeth on the skip ratchet wheel outnumber the deep teeth thereon, and all of the shallow teeth are grouped together adjacent to a deep tooth.

means for limiting the swing of the actuator arm to an extent substantially complementary to the arc traversed by the main shaft in power rotating from the starting position to the terminal position aforesaid. 

1. The combination which comprises: a cycle starter for starting and controlling a series of machine operations, said starter including a rotatable shaft, an electric motor in driving relation to said shaft, and a motor circuit including electric contact means closable to energize said motor incident to an initial manual part-rotation of said shaft, and to deenergize said drive mOtor as the shaft reaches a terminal limit of rotation; a coin slide including a slide plate receptive of a coin, and means for testing the coin, said slide plate having an end fully advanceable then fully retractable whenever a coin in the slide plate passes testing; and means operative to initiate a part-rotation of the shaft for energizing said drive motor only after at least two successive full advancements of the slide plate.
 2. The combination as defined by claim 1, wherein is included means for supporting independently of the coin slide, the rotation-initiating means aforesaid.
 3. The combination as defined by claim 1, wherein the cycle starter shaft provides support for the rotation-initiating means aforesaid.
 4. The combination as defined by claim 1, wherein is provided means on the cycle starter for supporting the rotation-initiating means aforesaid.
 5. The combination as defined by claim 1, wherein said rotation-initiating means and said coin slide are normally out of physical contact with one another.
 6. The combination as defined by claim 5, and wherein said rotation-initiating means includes an actuator arm movable between a home position in the path of advancement of the coin slide plate, and a position of displacement about the starter shaft axis, a pawl movable correspondingly with said actuator arm, and a pair of rotary ratchet wheels surrounding the cycle starter shaft, one of said ratchet wheels being fixed relative to said shaft, and the other of said ratchet wheels being rotatable as an idler relative to said shaft, and an arrangement of teeth on said ratchet wheels insuring tooth-by-tooth rotation of the idler wheel with full displacement of the actuator arm, and a partial rotation of said one ratchet wheel unitarily with the shaft, only after a plurality of single tooth rotary impulses of the idler wheel have been completed.
 7. The combination as defined by claim 6, wherein advancement of the slide plate is performed in a plane at approximate right angles to the axis of the cycle starter shaft.
 8. The combination as defined by claim 3, wherein advancement of the slide plate is performed in a plane at approximate right angles to the axis of the cycle starter shaft.
 9. The combination as defined by claim 6, which includes spring means operative normally to retract the coin slide and to urge the actuator arm toward home position.
 10. Cycle starting mechanism for a motor-driven electric contactor including a main shaft, an electric motor, a switch connected to said motor so as to control its operation, said motor connected to said main shaft so as to rotate it in one direction, said switch energizing said motor while it drives said main shaft and contactor from a starting position to a terminal position, through a circle arc less than a full circle; said starting mechanism comprising a toothed ratchet wheel fixed relative to the main shaft of the contactor, a selectively rockable actuator arm loosely mounted for rotation about the shaft, between a home position and a position of displacement, means tending to constantly urge said actuator arm toward the home position, a pawl spring biased toward engagement with the tooth of the ratchet wheel, means mounting the pawl for bodily movement with the actuator arm, the swing of the actuator arm being substantially complementary in extent to the arc traversed by the shaft in power rotating from the starting position to the terminal position aforesaid, and means operative to preclude engagement of the pawl with the tooth of the ratchet wheel, until the actuator arm has been rocked to and from the displaced position at least once without concurrent movement of the main shaft.
 11. The mechanism as defined by claim 10, wherein is included in combination, selectively adjustable means for fixing the actuator arm in different rotated positions relative to the tooth upon the ratchet wheel.
 12. In combination, a motor-driven electric contactor including a main shaft rotatable througH a complete circle, said shaft being power-rotatable in one direction from a starting position to a terminal position through a circle are less than a full circle in extent, a hub detachably fixed upon the shaft for rotation therewith, a toothed drive ratchet wheel drivingly fixed relative to the hub, an adjacent multiple-tooth skip ratchet wheel loosely surrounding the hub for concentric rotation relative to the drive ratchet wheel, one of said skip ratchet wheel teeth having a deep root dimension such as to effect registration with the tooth of the drive ratchet wheel, and other teeth on the skip ratchet wheel having each a shallow depth short of effecting registration with the tooth of said drive ratchet wheel, an adjustment plate apertured to loosely surround the hub for relative rotation, and an actuator arm apertured to surround the shaft for swinging movement about the main shaft axis and in close proximity to the adjustment plate, a pawl pivoted upon the adjustment plate, and means yieldingly urging the pawl toward both ratchet wheels to engage the deep tooth of the skip ratchet wheel concurrently with engaging the tooth of the drive ratchet wheel whenever said deep tooth and said drive ratchet wheel tooth are in registry, and to engage only the shallow tooth aforesaid whenever said deep tooth and said drive ratchet wheel tooth are out of registry, and means for selectively clamping the arm in various rotated positions upon the adjustment plate.
 13. The combination as defined by claim 12, including yielding means for constantly urging the actuator arm in a direction of rotation counter to that of the main shaft, and stationary stop means for limiting rotation of the arm by said yielding means last mentioned.
 14. The combination as defined by claim 13, wherein the number of shallow teeth on the skip ratchet wheel is at least equal to or greater than the number of deep teeth on said skip ratchet wheel.
 15. The combination as defined by claim 12, wherein the shallow teeth on the skip ratchet wheel outnumber the deep teeth thereon.
 16. The combination as defined by claim 13, wherein the shallow teeth on the skip ratchet wheel outnumber the deep teeth thereon, and all of the shallow teeth are grouped together adjacent to a deep tooth.
 17. The combination as defined by claim 15, including means for limiting the swing of the actuator arm to an extent substantially complementary to the arc traversed by the main shaft in power rotating from the starting position to the terminal position aforesaid.
 18. The combination as defined by claim 16, including means for limiting the swing of the actuator arm to an extent substantially complementary to the arc traversed by the main shaft in power rotating from the starting position to the terminal position aforesaid. 